A longitudinal cohort study in Italy suggested that non-dipping and reverse dipping blood pressure (BP) patterns are associated with an increased prevalence of cardiac autonomic neuropathy and reduced survival. The study recruited 349 diabetic patients (52% women, age 57.1±11.9 y, BMI 29.4±5.9 kg/m2, HbA1c 8.6±2.1%, 284 with type 2 diabetes) with 24-hour ambulatory BP and heart rate variability (HRV) monitoring from 1999. Dipping, non-dipping and reverse dipping status were defined as a ≥10% decline, <10% decline, and ≥0.1% increase in average night-time systolic BP (SBP) compared with average daytime SBP, respectively. During 6,251 person-years of follow-up (median follow-up 21.0 years), a total of 136 deaths occurred. Compared with dippers (n=166), non-dippers (n=144) and reverse dippers (n=39) showed progressively more of cardiac autonomic neuropathy (11%, 16% and 31%, respectively), low HRV (45% vs 53% vs 62%), 24-hour hypertension (40%, 60% and 67%), isolated nocturnal hypertension (5%, 27% and 49%), postural hypotension (14%, 26% and 43%), and less of white-coat hypertension (31%, 17% and 13%). Reverse dippers and non-dippers had progressively lower mean overall survival (OS) compared with dippers (16.1±5.3 years, 17.5±5.3 years and 18.6±4.6 years, respectively). Reverse dippers also showed an increased risk of all-cause mortality after adjustment for age, sex, BMI, office SBP, plasma glucose, and diabetes duration and type (HR 2.3). Patients with low HRV had reduced mean OS than those with high HRV (16.9±5.5 and 18.8±4.4, respectively) but similar adjusted risk (HR 1.3). There were no significant interactions between BP patterns, HRV and diabetes type on OS. The study supports administering antihypertensive medications in the evening rather than in the morning to reduce nocturnal BP. Abnormal circadian BP patterns and reduced HRV are established cardiovascular risk factors. Source: https://www.ahajournals.org/
